staging: fbtft: fix out of bound access

str was 16 bytes but was mentioned as 128 in snprintf.
again msg is 128 bytes but not sufficient to hold the complete debug
message of register values.
Now removed the use of str, msg and print the register values from the
loop.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fbtft/fbtft-core.c

@@ -1066,8 +1066,6 @@ static int fbtft_init_display_dt(struct fbtft_par *par)
 	const __be32 *p;
 	u32 val;
 	int buf[64], i, j;
-	char msg[128];
-	char str[16];
 
 	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
 
@@ -1093,13 +1091,11 @@ static int fbtft_init_display_dt(struct fbtft_par *par)
 				p = of_prop_next_u32(prop, p, &val);
 			}
 			/* make debug message */
-			msg[0] = '\0';
-			for (j = 0; j < i; j++) {
-				snprintf(str, 128, " %02X", buf[j]);
-				strcat(msg, str);
-			}
 			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
 				"init: write_register:%s\n", msg);
+			for (j = 0; j < i; j++)
+				fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+					      "buf[%d] = %02X\n", j, buf[j]);
 
 			par->fbtftops.write_register(par, i,
 				buf[0], buf[1], buf[2], buf[3],