Replace reboot-fastboot by reboot fastboot

Older host adb client do not recognize reboot-fastboot,
switch it for "adb reboot fastboot" which should be the
same.

Test: None
Bug: 117670584
Change-Id: Iec5230ca66ec18fe7d7c0ebd3f9ab9596a6e7b3c

fs_mgr/tests/adb-remount-test.sh

@@ -1026,7 +1026,7 @@ elif [ "${ANDROID_PRODUCT_OUT}" = "${ANDROID_PRODUCT_OUT%*/${H}}" ]; then
 elif [ -z "${ANDROID_HOST_OUT}" ]; then
   echo "${ORANGE}[  WARNING ]${NORMAL} please run lunch, skipping"
 else
-  adb reboot-fastboot ||
+  adb reboot fastboot ||
     die "fastbootd not supported (wrong adb in path?)"
   any_wait 2m &&
     inFastboot ||
@@ -1136,7 +1136,7 @@ if [ -n "${scratch_partition}" ]; then
 
   echo "${GREEN}[ RUN      ]${NORMAL} test fastboot flash to ${scratch_partition} recovery" >&2
 
-  adb reboot-fastboot ||
+  adb reboot fastboot ||
     die "Reboot into fastbootd"
   img=${TMPDIR}/adb-remount-test-${$}.img
   cleanup() {