Fix typo s/SASL_CONF_DIR/SASL_CONF_PATH/ in QEMU VNC code

The QEMU VNC client arg code has a long standing typo
of SASL_CONF_DIR when it should be SASL_CONF_PATH for
the env variable name.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/qemu/qemu_command.c

@@ -6541,7 +6541,7 @@ qemuBuildGraphicsVNCCommandLine(virQEMUDriverConfigPtr cfg,
             virBufferAddLit(&opt, ",sasl");
 
             if (cfg->vncSASLdir)
-                virCommandAddEnvPair(cmd, "SASL_CONF_DIR", cfg->vncSASLdir);
+                virCommandAddEnvPair(cmd, "SASL_CONF_PATH", cfg->vncSASLdir);
 
             /* TODO: Support ACLs later */
         }

tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.args

 LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
-SASL_CONF_DIR=/root/.sasl2 QEMU_AUDIO_DRV=none \
+SASL_CONF_PATH=/root/.sasl2 QEMU_AUDIO_DRV=none \
 /usr/bin/qemu -S -M pc -m 214 \
 -smp 1 -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb -hda \
 /dev/HostVG/QEMUGuest1 -net none -serial none -parallel none -vnc \

tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-tls.args

 LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
-SASL_CONF_DIR=/root/.sasl2 QEMU_AUDIO_DRV=none \
+SASL_CONF_PATH=/root/.sasl2 QEMU_AUDIO_DRV=none \
 /usr/bin/qemu -S -M pc -m 214 \
 -smp 1 -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb -hda \
 /dev/HostVG/QEMUGuest1 -net none -serial none -parallel none -vnc \