prevent jump on uninitialized value

workload is getting 'initialized' with stack garbage,
so later conditional check of !workload[0] in report()
is invalid.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
diff --git a/src/main.cpp b/src/main.cpp
index d8e2a47..7a1b976 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -356,7 +356,7 @@
 	int c;
 	bool wantreport = FALSE;
 	char filename[4096];
-	char workload[4096];
+	char workload[4096] = {0,};
 	int  iterations = 1;
 
 #ifndef DISABLE_TRYCATCH