refine build script

@@ -273,13 +273,13 @@ if [ $SRS_GPERF = YES ]; then CXXFLAGS="${CXXFLAGS} -fno-builtin-malloc -fno-bui
 # arm or i386/x86_64
 if [ $SRS_ARM_UBUNTU12 = YES ]; then
     cat << END > ${SRS_OBJS}/${SRS_MAKEFILE}
+GCC = ${SrsArmGCC}
 CXX = ${SrsArmCXX}
 AR = ${SrsArmAR}
 LINK = ${SrsArmCXX}
 END
 else
     cat << END > ${SRS_OBJS}/${SRS_MAKEFILE}
-CC = gcc
 GCC = gcc
 CXX = g++
 AR = ar

+GCC = gcc
+
 .PHONY: default clean help ssl nossl
 
 default: help
@@ -31,16 +33,16 @@ SRS_LIBRTMP_L = $(SRS_OBJS)/lib/srs_librtmp.a
 SRS_LIBSSL_L = $(SRS_OBJS)/openssl/lib/libssl.a $(SRS_OBJS)/openssl/lib/libcrypto.a
 
 srs_publish_nossl: srs_publish.c Makefile $(SRS_LIBRTMP_I) $(SRS_LIBRTMP_L)
-	gcc srs_publish.c $(SRS_LIBRTMP_L) -g -O0 -lstdc++ -o srs_publish_nossl
+	$(GCC) srs_publish.c $(SRS_LIBRTMP_L) -g -O0 -lstdc++ -o srs_publish_nossl
 
 srs_play_nossl: srs_play.c Makefile $(SRS_LIBRTMP_I) $(SRS_LIBRTMP_L)
-	gcc srs_play.c $(SRS_LIBRTMP_L) -g -O0 -lstdc++ -o srs_play_nossl
+	$(GCC) srs_play.c $(SRS_LIBRTMP_L) -g -O0 -lstdc++ -o srs_play_nossl
 
 srs_publish_ssl: srs_publish.c Makefile $(SRS_LIBRTMP_I) $(SRS_LIBRTMP_L) $(SRS_LIBSSL_L)
-	gcc srs_publish.c $(SRS_LIBRTMP_L) $(SRS_LIBSSL_L) -g -O0 -ldl -lstdc++ -o srs_publish_ssl
+	$(GCC) srs_publish.c $(SRS_LIBRTMP_L) $(SRS_LIBSSL_L) -g -O0 -ldl -lstdc++ -o srs_publish_ssl
 
 srs_play_ssl: srs_play.c Makefile $(SRS_LIBRTMP_I) $(SRS_LIBRTMP_L) $(SRS_LIBSSL_L)
-	gcc srs_play.c $(SRS_LIBRTMP_L) $(SRS_LIBSSL_L) -g -O0 -ldl -lstdc++ -o srs_play_ssl
+	$(GCC) srs_play.c $(SRS_LIBRTMP_L) $(SRS_LIBSSL_L) -g -O0 -ldl -lstdc++ -o srs_play_ssl
 
 # alias for publish/play with/without ssl
 ssl: srs_publish_ssl srs_play_ssl