patch 8.2.1975: Win32: memory leak when encoding conversion fails

Problem:    Win32: memory leak when encoding conversion fails.
Solution:   Free the allocated memory. (Ken Takata, closes #7277)
diff --git a/src/os_win32.c b/src/os_win32.c
index 52573fe..60c0463 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -3532,7 +3532,10 @@
 
 	wn = enc_to_utf16(fname, NULL);
 	if (wn == NULL)
+	{
+	    vim_free(p);
 	    return NULL;
+	}
 
 	// Try to retrieve the entire security descriptor.
 	err = GetNamedSecurityInfoW(
diff --git a/src/version.c b/src/version.c
index 06fa4d0..872c25a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1975,
+/**/
     1974,
 /**/
     1973,