Blackfin: otp: fix build after constification of args[]

The OTP code does a little shuffling of arguments that aren't really
necessary, so use a local variable instead to fix build errors now
that the args[] parameter is const.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/common/cmd_otp.c b/common/cmd_otp.c
index 56f08e0..eb93eb2 100644
--- a/common/cmd_otp.c
+++ b/common/cmd_otp.c
@@ -82,6 +82,7 @@
 
 int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
+	char *cmd;
 	uint32_t ret, base_flags;
 	bool prompt_user, force_read;
 	uint32_t (*otp_func)(uint32_t page, uint32_t flags, uint64_t *page_content);
@@ -93,21 +94,21 @@
 
 	prompt_user = false;
 	base_flags = 0;
-	if (!strcmp(argv[1], "read"))
+	cmd = argv[1];
+	if (!strcmp(cmd, "read"))
 		otp_func = bfrom_OtpRead;
-	else if (!strcmp(argv[1], "dump")) {
+	else if (!strcmp(cmd, "dump")) {
 		otp_func = bfrom_OtpRead;
 		force_read = true;
-	} else if (!strcmp(argv[1], "write")) {
+	} else if (!strcmp(cmd, "write")) {
 		otp_func = bfrom_OtpWrite;
 		base_flags = OTP_CHECK_FOR_PREV_WRITE;
 		if (!strcmp(argv[2], "--force")) {
-			argv[2] = argv[1];
 			argv++;
 			--argc;
 		} else
 			prompt_user = false;
-	} else if (!strcmp(argv[1], "lock")) {
+	} else if (!strcmp(cmd, "lock")) {
 		if (argc != 4)
 			goto usage;
 		otp_func = bfrom_OtpWrite;
@@ -175,7 +176,7 @@
 	}
 
 	printf("OTP memory %s: addr 0x%p  page 0x%03X  count %zu ... ",
-		argv[1], addr, page, count);
+		cmd, addr, page, count);
 
 	set_otp_timing(otp_func == bfrom_OtpWrite);
 	if (otp_func == bfrom_OtpWrite && check_voltage()) {