Blackfin arch: add missing gpio error handling to make sure we roll back requests in case one fails

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/arch/blackfin/kernel/bfin_gpio.c b/arch/blackfin/kernel/bfin_gpio.c
index b818a8d..979cf79 100644
--- a/arch/blackfin/kernel/bfin_gpio.c
+++ b/arch/blackfin/kernel/bfin_gpio.c
@@ -711,9 +711,15 @@
 	int ret;
 
 	for (cnt = 0; per[cnt] != 0; cnt++) {
+
 		ret = peripheral_request(per[cnt], label);
-		if (ret < 0)
-			return ret;
+
+		if (ret < 0) {
+			for ( ; cnt > 0; cnt--) {
+				peripheral_free(per[cnt - 1]);
+			}
+		return ret;
+		}
 	}
 
 	return 0;