testsuite: work around patch bug

testsuite: work around patch bug

Due to a CVE bug, the patch was modified to not allow following
symlinks out of the workdir.  However, this causes a bug when
there is a regular file out of the workdir which breaks the current
testsuite build.

Steps to reproduce:
  ./boot.sh
  mkdir _gcc && cd _gcc
  ../configure
  make
  [...]
  /bin/sh /home/fleitner/ovs/testsuite/build-aux/missing autom4te
  --language=autotest -I '..' -o ../tests/testsuite.tmp
  ../tests/testsuite.at
  patch -p0 ../tests/testsuite.tmp ../tests/testsuite.patch
  Invalid file name ../tests/testsuite.tmp -- skipping patch
  Makefile:5155: recipe for target '../tests/testsuite' failed
  make[2]: *** [../tests/testsuite] Error 1
  make[2]: Leaving directory
  '/home/fleitner/NetworkingServices/openvswitch/repo/testsuite/_gcc'
  Makefile:4087: recipe for target 'all-recursive' failed
  make[1]: *** [all-recursive] Error 1

Since it's just a temporary file, this patch changes to use the
workdir as the place to put the file.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>