playing with got on alpine, i noticed that `got revert -p' doesn't
show the prompt.  I'm assuming musl doesn't fflush implicitly on
getline, which is what show_change assumes.

ok?

diff -s /home/op/w/got
commit - c877c437470e41e7f70828c916ff40189b097fe2
path + /home/op/w/got (staged changes)
blob - e8369725fe5afccaf92cac20559a3594304240bd
blob + 1877932f7650a337705d19c325c27b9f594e54bf
--- got/got.c
+++ got/got.c
@@ -8119,6 +8119,7 @@ show_change(unsigned char status, const char *path, FI
 		return got_error_path(path, GOT_ERR_FILE_STATUS);
 	}
 
+	fflush(stdout);
 	return NULL;
 }