Close the file in fileio.exp test

I see the following fail in fileio.exp on mingw32 host gdb,

rename 1: ret = -1, errno = 13^M
^M
Breakpoint 2, stop () at fileio.c:76^M
76      static void stop () {}^M
(gdb) FAIL: gdb.base/fileio.exp: Rename a file

the test fails to rename a file which is not expected.  The previous
test test_write doesn't close the file, so the rename fails as a
result on Windows.  This patch fixes it by closing file in test_write,
and the fail goes away.

rename 1: ret = 0, errno = 0 OK^M
^M
Breakpoint 2, stop () at fileio.c:76^M
76      static void stop () {}^M
(gdb) PASS: gdb.base/fileio.exp: Rename a file

gdb/testsuite:

2014-10-29  Yao Qi  <yao@codesourcery.com>

	* gdb.base/fileio.c (test_write): Close the file.

1 files changed, 1 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/fileio.c b/gdb/testsuite/gdb.base/fileio.c
index b8c2698..29c32e0 100644
--- a/gdb/testsuite/gdb.base/fileio.c
+++ b/gdb/testsuite/gdb.base/fileio.c
@@ -169,6 +169,7 @@ test_write ()
       ret = write (fd, STRING, strlen (STRING));
       printf ("write 3: ret = %d, errno = %d %s\n", ret, errno,
 	      strerrno (errno));
+      close (fd);
     }
   else
     printf ("write 3: ret = %d, errno = %d\n", ret, errno);