Fix dlltool-failed test

Author: estebank

tests/ui/linkage-attr/raw-dylib/windows/dlltool-failed.stderr

@@ -1,7 +1,7 @@
 error: dlltool could not create import library with $DLLTOOL -d $DEF_FILE -D foo.dll -l $LIB_FILE $TARGET_MACHINE $ASM_FLAGS --no-leading-underscore $TEMP_PREFIX:
 
        $DLLTOOL: Syntax error in def file $DEF_FILE:1␍
-
+       
 
 error: aborting due to 1 previous error