shell32: Avoid hardcoding array lengths.

dlls/shell32/shelllink.c

@@ -2115,7 +2115,7 @@ static HRESULT ShellLink_SetAdvertiseInfo(IShellLinkImpl *This, LPCWSTR str)
 static BOOL ShellLink_GetVolumeInfo(LPCWSTR path, volume_info *volume)
 {
     const int label_sz = sizeof volume->label/sizeof volume->label[0];
-    WCHAR drive[4] = { path[0], ':', '\\', 0 };
+    WCHAR drive[] = { path[0], ':', '\\', 0 };
     BOOL r;
 
     volume->type = GetDriveTypeW(drive);

dlls/shell32/shfldr_unixfs.c

@@ -1609,7 +1609,7 @@ static HRESULT WINAPI UnixFolder_IPersistFolder3_Initialize(IPersistFolder3* ifa
 
     if (current->mkid.cb) {
         if (_ILIsDrive(current)) {
-            WCHAR wszDrive[4] = { '?', ':', '\\', 0 };
+            WCHAR wszDrive[] = { '?', ':', '\\', 0 };
             wszDrive[0] = (WCHAR)*_ILGetTextPointer(current);
             if (!UNIXFS_get_unix_path(wszDrive, szBasePath))
                 return E_FAIL;