checkpatch: more comprehensive split strings warning

The current checkpatch test for split strings does not find several
cases that should be found.

For instance:

 		/* Else poor success; go back to mode in "active" table */
 		} else {
 			IWL_DEBUG_RATE(mvm,
-				       "LQ: GOING BACK TO THE OLD TABLE suc=%d cur-tpt=%d old-tpt=%d\n",
+				       "GOING BACK TO THE OLD TABLE: SR %d "
+				       "cur-tpt %d old-tpt %d\n",
 				       window->success_ratio,
 				       window->average_tpt,
 				      lq_sta->last_tpt);

does not currently emit a warning.

Improve the test to find these cases.

Add more exceptions to reduce false positives for assembly and octal/hex
string constants.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -2049,16 +2049,12 @@ sub process {
 		}
 
 # Check for user-visible strings broken across lines, which breaks the ability
-# to grep for the string.  Limited to strings used as parameters (those
-# following an open parenthesis), which almost completely eliminates false
-# positives, as well as warning only once per parameter rather than once per
-# line of the string.  Make an exception when the previous string ends in a
-# newline (multiple lines in one string constant) or \n\t (common in inline
-# assembly to indent the instruction on the following line).
+# to grep for the string.  Make exceptions when the previous string ends in a
+# newline (multiple lines in one string constant) or '\t', '\r', ';', or '{'
+# (common in inline assembly) or is a octal \123 or hexadecimal \xaf value
 		if ($line =~ /^\+\s*"/ &&
 		    $prevline =~ /"\s*$/ &&
-		    $prevline =~ /\(/ &&
-		    $prevrawline !~ /\\n(?:\\t)*"\s*$/) {
+		    $prevrawline !~ /(?:\\(?:[ntr]|[0-7]{1,3}|x[0-9a-fA-F]{1,2})|;\s*|\{\s*)"\s*$/) {
 			WARN("SPLIT_STRING",
 			     "quoted string split across lines\n" . $hereprev);
 		}