m68k: Return semihosting errno values correctly

Fixing a simple typo, s/errno/err/, that caused
the error status from GDB semihosted system calls
to be returned incorrectly.
Signed-off-by: NMeador Inge <meadori@codesourcery.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

target-m68k/m68k-semi.c

@@ -150,7 +150,7 @@ static void m68k_semi_cb(CPUM68KState *env, target_ulong ret, target_ulong err)
     }
     /* FIXME - handle put_user() failure */
     put_user_u32(ret, args);
-    put_user_u32(errno, args + 4);
+    put_user_u32(err, args + 4);
 }
 
 #define ARG(n)					\