toolchain/wrapper.sh: Replace read with read -r

Without -r, backslashes would get mangled.

Found with shellcheck.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

target/toolchain/files/wrapper.sh

@@ -30,7 +30,7 @@ TARGET_TOOLCHAIN_TRIPLET=${REALNAME_BASE%-*}
 BINARY=${PROGNAME##*-}
 
 # Parse our tool name, splitting it at '-' characters.
-IFS=- read TOOLCHAIN_ARCH TOOLCHAIN_BUILDROOT TOOLCHAIN_OS TOOLCHAIN_PLATFORM PROGNAME << EOF
+IFS=- read -r TOOLCHAIN_ARCH TOOLCHAIN_BUILDROOT TOOLCHAIN_OS TOOLCHAIN_PLATFORM PROGNAME << EOF
 $REALNAME_BASE
 EOF