Bump buildroot to 2019.02

bsp/buildroot/toolchain/helpers.mk

@@ -241,14 +241,11 @@ check_glibc = \
 # $2: cross-readelf path
 check_musl = \
 	__CROSS_CC=$(strip $1) ; \
-	__CROSS_READELF=$(strip $2) ; \
-	echo 'void main(void) {}' | $${__CROSS_CC} -x c -o $(BUILD_DIR)/.br-toolchain-test.tmp - >/dev/null 2>&1; \
-	if ! $${__CROSS_READELF} -l $(BUILD_DIR)/.br-toolchain-test.tmp 2> /dev/null | grep 'program interpreter: /lib/ld-musl' -q; then \
-		rm -f $(BUILD_DIR)/.br-toolchain-test.tmp*; \
+	libc_a_path=`$${__CROSS_CC} -print-file-name=libc.a` ; \
+	if ! strings $${libc_a_path} | grep -q MUSL_LOCPATH ; then \
 		echo "Incorrect selection of the C library" ; \
 		exit -1; \
-	fi ; \
-	rm -f $(BUILD_DIR)/.br-toolchain-test.tmp*
+	fi
 
 #
 # Check the conformity of Buildroot configuration with regard to the