bsd-user: Rename TARGET_ERESTARTSYS to QEMU_ERESTARTSYS

This value is fully internal to qemu, and so is not a TARGET define.
We use this as an extra marker for both host and target errno.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

bsd-user/errno_defs.h

@@ -151,6 +151,6 @@
 /* Internal errors: */
 #define TARGET_EJUSTRETURN      254             /* Just return without modifing regs */
 #define TARGET_ERESTART         255             /* Restart syscall */
-#define TARGET_ERESTARTSYS      TARGET_ERESTART /* Linux compat */
+#define QEMU_ERESTARTSYS        TARGET_ERESTART
 
 #endif /* !  _ERRNO_DEFS_H_ */