MdeModulePkg/EbcDebugger: Add check for invalid 'CommandArg'
Add checks for the return value of function Atoi() in EdbCmdBreakpoint.c.
If the input parameter 'CommandArg' contains non-digit character, print
corresponding error message.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Hao Wu <hao.a.wu@intel.com> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>