Enter into userspace fastboot only if the device supports it

Test: For devices not supporting logical partitions, 'adb reboot
fastboot' command reboots into  Android.
Bug: 78793464

Change-Id: Ie6c6ccdebfee9302a9996ac5bc66069dbd817987
diff --git a/recovery_main.cpp b/recovery_main.cpp
index c3168fc..c4e3af2 100644
--- a/recovery_main.cpp
+++ b/recovery_main.cpp
@@ -364,7 +364,8 @@
         std::string option = OPTIONS[option_index].name;
         if (option == "locale") {
           locale = optarg;
-        } else if (option == "fastboot") {
+        } else if (option == "fastboot" &&
+                   android::base::GetBoolProperty("ro.boot.logical_partitions", false)) {
           fastboot = true;
         }
         break;