config: Add missing \ in bootanimation pick

Change-Id: Id61a196f97115c70b7d1dcf84fe830b72834a17c
diff --git a/config/common.mk b/config/common.mk
index 00a536c..6c4d8f9 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -15,7 +15,7 @@
 # find the appropriate size and set
 define check_and_set_bootanimation
 $(eval TARGET_BOOTANIMATION_NAME := $(shell \
-  if [ -z "$(TARGET_BOOTANIMATION_NAME)" ]; then
+  if [ -z "$(TARGET_BOOTANIMATION_NAME)" ]; then \
     if [ "$(1)" -le "$(TARGET_BOOTANIMATION_SIZE)" ]; then \
       echo $(1); \
       exit 0; \