inetcomm: Void functions should not return a value

[Andrew Talbot]

Changelog:
    inetcomm: Void functions should not return a value.

diff --git a/dlls/inetcomm/mimeole.c b/dlls/inetcomm/mimeole.c
index 3ee7281..1e39f27 100644
--- a/dlls/inetcomm/mimeole.c
+++ b/dlls/inetcomm/mimeole.c
@@ -2786,7 +2786,7 @@ static void WINAPI MimeAlloc_Free(
         IMimeAllocator* iface,
         LPVOID pv)
 {
-    return CoTaskMemFree(pv);
+    CoTaskMemFree(pv);
 }
 
 static ULONG WINAPI MimeAlloc_GetSize(