crash_dump: is_kdump_kernel can be boolean

Make is_kdump_kernel return bool due to this particular function only
using either one or zero as its return value.

No functional change.

Link: http://lkml.kernel.org/r/1513308799-19232-8-git-send-email-baiyaowei@cmss.chinamobile.com
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/crash_dump.h

@@ -2,13 +2,13 @@
 #ifndef LINUX_CRASH_DUMP_H
 #define LINUX_CRASH_DUMP_H
 
-#ifdef CONFIG_CRASH_DUMP
 #include <linux/kexec.h>
 #include <linux/proc_fs.h>
 #include <linux/elf.h>
 
 #include <asm/pgtable.h> /* for pgprot_t */
 
+#ifdef CONFIG_CRASH_DUMP
 #define ELFCORE_ADDR_MAX	(-1ULL)
 #define ELFCORE_ADDR_ERR	(-2ULL)
 
@@ -52,13 +52,13 @@ void vmcore_cleanup(void);
  * has passed the elf core header address on command line.
  *
  * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
- * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
- * previous kernel.
+ * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
+ * of previous kernel.
  */
 
-static inline int is_kdump_kernel(void)
+static inline bool is_kdump_kernel(void)
 {
-	return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
+	return elfcorehdr_addr != ELFCORE_ADDR_MAX;
 }
 
 /* is_vmcore_usable() checks if the kernel is booting after a panic and
@@ -89,7 +89,7 @@ extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
 extern void unregister_oldmem_pfn_is_ram(void);
 
 #else /* !CONFIG_CRASH_DUMP */
-static inline int is_kdump_kernel(void) { return 0; }
+static inline bool is_kdump_kernel(void) { return 0; }
 #endif /* CONFIG_CRASH_DUMP */
 
 extern unsigned long saved_max_pfn;