roots: Remove get_system_root and logical_partitions_mapped.

Test: TreeHugger
Test: Boot into recovery on blueline. Choose "Mount system partition".
Change-Id: Iac475d18ce2415de09dc0bf009ad4cf0383ffede
diff --git a/recovery_main.cpp b/recovery_main.cpp
index b999505..aba9c5d 100644
--- a/recovery_main.cpp
+++ b/recovery_main.cpp
@@ -42,6 +42,7 @@
 #include <android-base/unique_fd.h>
 #include <bootloader_message/bootloader_message.h>
 #include <cutils/sockets.h>
+#include <fs_mgr/roots.h>
 #include <private/android_logger.h> /* private pmsg functions */
 #include <selinux/android.h>
 #include <selinux/label.h>
@@ -505,7 +506,7 @@
       }
 
       case Device::ENTER_FASTBOOT:
-        if (logical_partitions_mapped()) {
+        if (android::fs_mgr::LogicalPartitionsMapped()) {
           ui->Print("Partitions may be mounted - rebooting to enter fastboot.");
           Reboot("fastboot");
         } else {