scripts: dtc: fix compile warnings

Fix following compile warnings:

scripts/dtc/flattree.c: In function ‘flat_read_mem_reserve’:
scripts/dtc/flattree.c:700:14: warning: variable ‘p’ set but not used
	[-Wunused-but-set-variable]

scripts/dtc/dtc.c: In function ‘main’:
scripts/dtc/dtc.c:104:17: warning: variable ‘check’ set but not used
	[-Wunused-but-set-variable]

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/scripts/dtc/dtc.c b/scripts/dtc/dtc.c
index 451c92d..2ef5e2e 100644
--- a/scripts/dtc/dtc.c
+++ b/scripts/dtc/dtc.c
@@ -101,7 +101,7 @@
 	const char *outform = "dts";
 	const char *outname = "-";
 	const char *depname = NULL;
-	int force = 0, check = 0, sort = 0;
+	int force = 0, sort = 0;
 	const char *arg;
 	int opt;
 	FILE *outf = NULL;
@@ -143,9 +143,6 @@
 		case 'f':
 			force = 1;
 			break;
-		case 'c':
-			check = 1;
-			break;
 		case 'q':
 			quiet++;
 			break;