Use LoadLibrary instead of LoadLibraryA.

LoadLibrary can either point to LoadLibraryA or LoadLibraryW depending
on the system and build options, so let's use LoadLibrary everywhere
for consistency. Also, wrap static argument strings with _T() so that
they're automatically in the right format.

src/misc/mtime.c

@@ -225,12 +225,12 @@ mtime_t mdate( void )
            (may also be true, for single cores with adaptive
             CPU frequency and active power management?)
         */
-        HINSTANCE h_Kernel32 = LoadLibraryA("kernel32.dll");
+        HINSTANCE h_Kernel32 = LoadLibrary(_T("kernel32.dll"));
         if(h_Kernel32)
         {
             void WINAPI (*pf_GetSystemInfo)(LPSYSTEM_INFO);
             pf_GetSystemInfo = (void WINAPI (*)(LPSYSTEM_INFO))
-                                GetProcAddress(h_Kernel32, "GetSystemInfo");
+                                GetProcAddress(h_Kernel32, _T("GetSystemInfo"));
             if(pf_GetSystemInfo)
             {
                SYSTEM_INFO system_info;

src/misc/threads.c

@@ -174,12 +174,12 @@ int __vlc_threads_init( vlc_object_t *p_this )
             HINSTANCE hInstLib;
 
             /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
-            hInstLib = LoadLibrary( "kernel32" );
+            hInstLib = LoadLibrary(_T("kernel32"));
             if( hInstLib )
             {
                 pf_SignalObjectAndWait =
                     (SIGNALOBJECTANDWAIT)GetProcAddress( hInstLib,
-                                                     "SignalObjectAndWait" );
+                                                  _T("SignalObjectAndWait") );
             }
         }