fix build failed for linux.

@@ -373,7 +373,7 @@ fi
 #####################################################################################
 if [ $SRS_EXPORT_LIBRTMP_PROJECT = NO ]; then
     # check the arm flag file, if flag changed, need to rebuild the st.
-    _ST_MAKE=linux-debug && _ST_EXTRA_CFLAGS="-DMD_HAVE_EPOLL"
+    _ST_MAKE=linux-debug && _ST_EXTRA_CFLAGS="EXTRA_CFLAGS=-DMD_HAVE_EPOLL"
     # for osx, use darwin for st, donot use epoll.
     if [ $OS_IS_OSX = YES ]; then
         _ST_MAKE=darwin-debug && _ST_EXTRA_CFLAGS=""
@@ -392,8 +392,8 @@ if [ $SRS_EXPORT_LIBRTMP_PROJECT = NO ]; then
                 rm -rf ${SRS_OBJS}/st-1.9 && cd ${SRS_OBJS} && 
                 unzip -q ../3rdparty/st-1.9.zip && cd st-1.9 && 
                 patch -p0 -R < ../../3rdparty/patches/1.st.arm.patch &&
-                make CC=${SrsArmCC} AR=${SrsArmAR} LD=${SrsArmLD} RANDLIB=${SrsArmRANDLIB} \
-                    EXTRA_CFLAGS=${_ST_EXTRA_CFLAGS} ${_ST_MAKE} &&
+                make ${_ST_MAKE} CC=${SrsArmCC} AR=${SrsArmAR} LD=${SrsArmLD} RANDLIB=${SrsArmRANDLIB} \
+                    EXTRA_CFLAGS=${_ST_EXTRA_CFLAGS} &&
                 cd .. && rm -rf st && ln -sf st-1.9/obj st &&
                 cd .. && touch ${SRS_OBJS}/_flag.st.arm.tmp
             )