MIPS: ftrace: Tweak safe_load()/safe_store() macros

Due to name collision in ftrace safe_load and safe_store macros,
these macros cannot take expressions as operands.

For example, compiler will complain for a macro call like the following:
  safe_store_code(new_code2, ip + 4, faulted);

  arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
     : [dst] "r" (dst), [src] "r" (src)\
        ^
  arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
    safe_store_code(new_code2, ip + 4, faulted);
    ^
  arch/mips/kernel/ftrace.c:118:32: error: undefined named operand 'ip + 4'
    safe_store_code(new_code2, ip + 4, faulted);
                                  ^
  arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
     : [dst] "r" (dst), [src] "r" (src)\
        ^
  arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
    safe_store_code(new_code2, ip + 4, faulted);
    ^

This build error is triggered by a4671094 [MIPS: ftrace: Fix icache flush
range error].  Tweak variable naming in those macros to allow flexible
operands.

Signed-off-by: Viller Hsiao <villerhsiao@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
Cc: mingo@redhat.com
Cc: Qais.Yousef@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6622/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/ftrace.h

@@ -22,12 +22,12 @@ extern void _mcount(void);
 #define safe_load(load, src, dst, error)		\
 do {							\
 	asm volatile (					\
-		"1: " load " %[" STR(dst) "], 0(%[" STR(src) "])\n"\
-		"   li %[" STR(error) "], 0\n"		\
+		"1: " load " %[tmp_dst], 0(%[tmp_src])\n"	\
+		"   li %[tmp_err], 0\n"			\
 		"2:\n"					\
 							\
 		".section .fixup, \"ax\"\n"		\
-		"3: li %[" STR(error) "], 1\n"		\
+		"3: li %[tmp_err], 1\n"			\
 		"   j 2b\n"				\
 		".previous\n"				\
 							\
@@ -35,8 +35,8 @@ do {							\
 		STR(PTR) "\t1b, 3b\n\t"			\
 		".previous\n"				\
 							\
-		: [dst] "=&r" (dst), [error] "=r" (error)\
-		: [src] "r" (src)			\
+		: [tmp_dst] "=&r" (dst), [tmp_err] "=r" (error)\
+		: [tmp_src] "r" (src)			\
 		: "memory"				\
 	);						\
 } while (0)
@@ -44,12 +44,12 @@ do {							\
 #define safe_store(store, src, dst, error)	\
 do {						\
 	asm volatile (				\
-		"1: " store " %[" STR(src) "], 0(%[" STR(dst) "])\n"\
-		"   li %[" STR(error) "], 0\n"	\
+		"1: " store " %[tmp_src], 0(%[tmp_dst])\n"\
+		"   li %[tmp_err], 0\n"		\
 		"2:\n"				\
 						\
 		".section .fixup, \"ax\"\n"	\
-		"3: li %[" STR(error) "], 1\n"	\
+		"3: li %[tmp_err], 1\n"		\
 		"   j 2b\n"			\
 		".previous\n"			\
 						\
@@ -57,8 +57,8 @@ do {						\
 		STR(PTR) "\t1b, 3b\n\t"		\
 		".previous\n"			\
 						\
-		: [error] "=r" (error)		\
-		: [dst] "r" (dst), [src] "r" (src)\
+		: [tmp_err] "=r" (error)	\
+		: [tmp_dst] "r" (dst), [tmp_src] "r" (src)\
 		: "memory"			\
 	);					\
 } while (0)