[U-Boot] [PATCH] dts/Makefile: Check for empty $(LDSCRIPT)

[Horst Kronstorfer]

Make sure that $(LDSCRIPT) is not empty before calling process_lds
with 'cat $(LDSCRIPT)' else cat will block waiting for input from
stdin.

Signed-off-by: Horst Kronstorfer <hkronsto at frequentis.com>
---
 dts/Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/dts/Makefile b/dts/Makefile
index 402dfe1..9a54ca5 100644
--- a/dts/Makefile
+++ b/dts/Makefile
@@ -66,8 +66,9 @@ $(obj)dt.o: $(DT_BIN)
 	# We look in the LDSCRIPT first.
 	# Then try the linker which should give us the answer.
 	# Then check it worked.
-	oformat=`$(call process_lds,cat $(LDSCRIPT),FORMAT)` ;\
-	oarch=`$(call process_lds,cat $(LDSCRIPT),ARCH)` ;\
+	[ -n "$(LDSCRIPT)" ] && \
+		oformat=`$(call process_lds,cat $(LDSCRIPT),FORMAT)` && \
+		oarch=`$(call process_lds,cat $(LDSCRIPT),ARCH)` ;\
 	\
 	[ -z $${oformat} ] && \
 		oformat=`$(call process_lds,$(GET_LDS),FORMAT)` ;\
-- 
1.7.11.1