vmmon: quick workaround for objtool warnings

As discussed in

  https://bugzilla.suse.com/show_bug.cgi?id=1059674

the reason for multiple objtool warnings is the fact that vmmon module
defines its own Panic() function which never returns. While it is marked as
such which is used by the compiler for optimization, there is no way to
find this from object file.

While this seems innocuous, it might result in problems with unwinder
later. The quickest way around is to replace vmmon's own Panic() with
standard kernel panic() until a cleaner solution is found.

vmmon-only/include/vm_assert.h

@@ -67,6 +67,7 @@ extern "C" {
 #if defined (VMKPANIC) 
 #include "vmk_assert.h"
 #else /* !VMKPANIC */
+#include <linux/kernel.h>
 #define _ASSERT_PANIC(name) \
            Panic(_##name##Fmt "\n", __FILE__, __LINE__)
 #define _ASSERT_PANIC_BUG(bug, name) \
@@ -107,7 +108,7 @@ NORETURN void Panic_NoSave(const char *fmt, ...) PRINTF_DECL(1, 2);
 } while(0)
 
 #else
-NORETURN void Panic(const char *fmt, ...) PRINTF_DECL(1, 2);
+#define Panic panic
 #endif
 
 void LogThrottled(uint32 *count, const char *fmt, ...) PRINTF_DECL(2, 3);