MdePkg: Remove "assert" from SmmCpuRendevousLibNull.c

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3931

Some drivers will break down when they use
SmmWaitForAllProcessor() which from SmmCpuRendezvousLibNull.c.
Removing the code "ASSERT(False)" will make consumer
work normally if they keep default setting for sync mode.

Cc: Michael D Kinney <[email protected]>
Cc: Liming Gao <[email protected]>

Signed-off-by: Zhihao Li <[email protected]>
Reviewed-by: Liming Gao <[email protected]>

Author: zhihaoli1064

MdePkg/Library/SmmCpuRendezvousLibNull/SmmCpuRendezvousLibNull.c

@@ -24,6 +24,5 @@ SmmWaitForAllProcessor (
   IN BOOLEAN  BlockingMode
   )
 {
-  ASSERT (FALSE);
   return EFI_SUCCESS;
 }