checkpatch: warn when missing newline in return sysfs_emit() formats

return sysfs_emit() uses should include a newline.

Suggest adding a newline when one is missing.
Add one using --fix too.

Link: https://lkml.kernel.org/r/aa1819fa5faf786573df298e5e2e7d357ba7d4ad.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -7198,6 +7198,17 @@ sub process {
 			     "Using $1 should generally have parentheses around the comparison\n" . $herecurr);
 		}
 
+# return sysfs_emit(foo, fmt, ...) fmt without newline
+		if ($line =~ /\breturn\s+sysfs_emit\s*\(\s*$FuncArg\s*,\s*($String)/ &&
+		    substr($rawline, $-[6], $+[6] - $-[6]) !~ /\\n"$/) {
+			my $offset = $+[6] - 1;
+			if (WARN("SYSFS_EMIT",
+				 "return sysfs_emit(...) formats should include a terminating newline\n" . $herecurr) &&
+			    $fix) {
+				substr($fixed[$fixlinenr], $offset, 0) = '\\n';
+			}
+		}
+
 # nested likely/unlikely calls
 		if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) {
 			WARN("LIKELY_MISUSE",