cmd: mtdparts: fix uninitialized variable warning

commit 06a040a31bcf ("cmd: mtdparts: fix null pointer dereference in parse_mtdparts")
removed the initialization of a pointer variable, which is
subsequently used in a debug() call. This produces an uninitialized
variable warning, when compiling with DEBUG defined.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
diff --git a/cmd/mtdparts.c b/cmd/mtdparts.c
index 112bf1f..683c48b 100644
--- a/cmd/mtdparts.c
+++ b/cmd/mtdparts.c
@@ -1556,7 +1556,7 @@
 	int err = 1;
 	char tmp_parts[MTDPARTS_MAXLEN];
 
-	debug("\n---parse_mtdparts---\nmtdparts = %s\n\n", p);
+	debug("\n---parse_mtdparts---\nmtdparts = %s\n\n", mtdparts);
 
 	/* delete all devices and partitions */
 	if (mtd_devices_init() != 0) {