perf target: Fix check on buffer size

It was a mistake just replace assert to BUG_ON since its condition
should be negated. Fix it.

Signed-off-by: Namhyung Kim <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ulrich Drepper <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

tools/perf/util/target.c

@@ -110,7 +110,7 @@ int perf_target__strerror(struct perf_target *target, int errnum,
 	int idx;
 	const char *msg;
 
-	BUG_ON(buflen > 0);
+	BUG_ON(buflen == 0);
 
 	if (errnum >= 0) {
 		const char *err = strerror_r(errnum, buf, buflen);