kernel/svc: Mark GetThreadList() and UnmapProcessCodeMemory() as internally linked

These are only used from within this translation unit, so they don't
need to have external linkage. They were intended to be marked with this
anyways to be consistent with the other service functions.

src/core/hle/kernel/svc.cpp

@@ -1255,8 +1255,8 @@ static ResultCode MapProcessCodeMemory(Core::System& system, Handle process_hand
     return vm_manager.MapCodeMemory(dst_address, src_address, size);
 }
 
-ResultCode UnmapProcessCodeMemory(Core::System& system, Handle process_handle, u64 dst_address,
-                                  u64 src_address, u64 size) {
+static ResultCode UnmapProcessCodeMemory(Core::System& system, Handle process_handle,
+                                         u64 dst_address, u64 src_address, u64 size) {
     LOG_DEBUG(Kernel_SVC,
               "called. process_handle=0x{:08X}, dst_address=0x{:016X}, src_address=0x{:016X}, "
               "size=0x{:016X}",
@@ -2183,8 +2183,8 @@ static ResultCode GetProcessList(Core::System& system, u32* out_num_processes,
     return RESULT_SUCCESS;
 }
 
-ResultCode GetThreadList(Core::System& system, u32* out_num_threads, VAddr out_thread_ids,
-                         u32 out_thread_ids_size, Handle debug_handle) {
+static ResultCode GetThreadList(Core::System& system, u32* out_num_threads, VAddr out_thread_ids,
+                                u32 out_thread_ids_size, Handle debug_handle) {
     // TODO: Handle this case when debug events are supported.
     UNIMPLEMENTED_IF(debug_handle != InvalidHandle);