ShellPkg: Remove ASSERT

This change removes ASSERT statements and replaces them with logic to break out of the loop.  This both prevents spinning forever and prevents processing the returned data from the function that failed.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15133 6f19259b-4bc3-4df7-8a09-765794883524
ShellPkg: Remove ASSERT

This change removes ASSERT statements and replaces them with logic to break out of the loop.  This both prevents spinning forever and prevents processing the returned data from the function that failed.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15134 6f19259b-4bc3-4df7-8a09-765794883524
ShellPkg: Return the failure

This change returns the error code when they keyboard fails to read instead of potentially spinning endlessly.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15135 6f19259b-4bc3-4df7-8a09-765794883524