ci/build-all-defconfigs.sh: Fix output directory handling

There's a longstanding issue in the ci/build-all-defconfigs.sh where it
erroneously uses "or" as part of the test syntax. The command fails and
since it's a sanity check, it doesn't have any consequences, e.g.:

  + for p in ${PLATFORM_LIST}
  + DEFCONFIGS+=($p$CONFIGTAG)
  + '[' -z /output-ubuntu1804 or '!' -d /output-ubuntu1804 ']'
  ./ci/build-all-defconfigs.sh: line 59: [: too many arguments

Even if the original intention seemed to be to check for a non-empty and
valid directory, the script was creating a completely new directory, and
that is apparently the CI's environment assumption here as well.

Remove check altogether since getopt "o:" will always give a non-empty
$OUTDIR, and that directory is expected to be created anyway.

Signed-off-by: Klaus Heinrich Kiwi <klaus@linux.vnet.ibm.com>
diff --git a/ci/build-all-defconfigs.sh b/ci/build-all-defconfigs.sh
index e1455b2..096ffbe 100755
--- a/ci/build-all-defconfigs.sh
+++ b/ci/build-all-defconfigs.sh
@@ -56,11 +56,6 @@
         done
 fi
 
-if [ -z "${OUTDIR}" or ! -d "${OUTDIR}" ]; then
-	echo "No output directory specified"
-	exit 1;
-fi
-
 if [ -z "$CCACHE_DIR" ]; then
 	CCACHE_DIR=`pwd`/.op-build_ccache
 fi
@@ -78,7 +73,7 @@
 fi
 
 for i in ${DEFCONFIGS[@]}; do
-	export O=${OUTDIR}-$i
+	export O=${OUTDIR}/$i
 	rm -rf $O
         op-build O=$O $i
 	./buildroot/utils/config --file $O/.config --set-val BR2_CCACHE y