scripts: use OE_TMPDIR instead of TMPDIR external variable

On OpenSUSE within an X session, TMPDIR is set to the system temporary
directory (/tmp) which is incorrect for these scripts. Thus, change
runqemu and oe-setup-rpmrepo to use OE_TMPDIR from the external
environment rather than TMPDIR.

Fixes [YOCTO #1530]

(From OE-Core rev: 4e24c10952c7a52af7f2447595fd484692d35534)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu

@@ -55,6 +55,11 @@ SCRIPT_QEMU_OPT=""
 SCRIPT_QEMU_EXTRA_OPT=""
 SCRIPT_KERNEL_OPT=""
 
+# Don't use TMPDIR from the external environment, it may be a distro
+# variable pointing to /tmp (e.g. within X on OpenSUSE)
+# Instead, use OE_TMPDIR for passing this in externally.
+TMPDIR="$OE_TMPDIR"
+
 # Determine whether the file is a kernel or QEMU image, and set the
 # appropriate variables
 process_filename() {
@@ -260,7 +265,7 @@ SPITZ_DEFAULT_FSTYPE=ext3
 
 setup_tmpdir() {
     if [ -z "$TMPDIR" ]; then
-        # BUILDDIR unset, try and get TMPDIR from bitbake
+        # Try to get TMPDIR from bitbake
         type -P bitbake &>/dev/null || {
             echo "In order for this script to dynamically infer paths";
             echo "to kernels or filesystem images, you either need";