Fix --with-cmodel option

When passed with `--without-cmodel`, cmodel will get value `no` which is
unexpected.

Signed-off-by: demin.han <[email protected]>

Author: demin-han

configure

@@ -4177,10 +4177,13 @@ fi
 if test ${with_cmodel+y}
 then :
   withval=$with_cmodel;
+else $as_nop
+  with_cmodel=no
+
 fi
 
 
-if test "x$with_cmodel" != x
+if test "x$with_cmodel" != xno
 then :
   cmodel=-mcmodel=$with_cmodel
 

configure.ac

@@ -177,10 +177,10 @@ AC_ARG_WITH(cmodel,
 	[AS_HELP_STRING([--with-cmodel],
 		[Select the code model to use when building libc and libgcc @<:@--with-cmodel=medlow@:>@])],
 	[],
-	[]
+	[with_cmodel=no]
 	)
 
-AS_IF([test "x$with_cmodel" != x],
+AS_IF([test "x$with_cmodel" != xno],
 	[AC_SUBST(cmodel, -mcmodel=$with_cmodel)],
 	[AC_SUBST(cmodel, -mcmodel=medlow)])