tools/cgsnapshot: Fix Coverity uninitialized variable warning

Coverity reported the following uninitialized variable warning:

CID 465887: (#1 of 1): Uninitialized scalar variable (UNINIT)
32. uninit_use_in_call: Using uninitialized value *wl_file when calling load_list.

Fix the issue by initializing the char[] wl_file with '\0', and also
initialize dl_file similarly as a best practice.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>

Author: kamalesh-babulal

src/tools/cgsnapshot.c

@@ -743,8 +743,8 @@ int main(int argc, char *argv[])
 	};
 
 	cont_name_t wanted_cont[CG_CONTROLLER_MAX];
-	char bl_file[FILENAME_MAX];  /* denylist file name */
-	char wl_file[FILENAME_MAX];  /* allowlist file name */
+	char bl_file[FILENAME_MAX] = { "\0" };  /* denylist file name */
+	char wl_file[FILENAME_MAX] = { "\0" };  /* allowlist file name */
 	int ret = 0, err;
 	int c_number = 0;
 	int c, i;