perf_counter tools: Fix uninitialized variable in perf-report.c

# make prefix=/usr/local V=1
gcc -o builtin-report.o -c -O2 -ggdb3 -Wall -Werror -Wstrict-prototypes -Wmissing-declarations -Wmissing-prototypes -std=gnu99 -Wdeclaration-after-statement   -DSHA1_HEADER='<openssl/sha.h>'  builtin-report.c
cc1: warnings being treated as errors
builtin-report.c: In function ‘__cmd_report’:
builtin-report.c:626: error: ‘cwdlen’ may be used uninitialized in this function

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>

Documentation/perf_counter/builtin-report.c

@@ -653,8 +653,10 @@ static int __cmd_report(void)
 			return EXIT_FAILURE;
 		}
 		cwdlen = strlen(cwd);
-	} else
+	} else {
 		cwdp = NULL;
+		cwdlen = 0;
+	}
 remap:
 	buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
 			   MAP_SHARED, input, offset);