tools: zynqimage: Clean up check_params

Clean up the param checking, removing some code paths that will never
happen.

Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Tom Rini <trini@konsulko.com>
Reported-by: Coverity (CID 133251)
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

tools/zynqimage.c

@@ -212,8 +212,7 @@ static int zynqimage_check_params(struct image_tool_params *params)
 		return -1;
 	}
 
-	return !((params->lflag || params->dflag) ||
-			(params->dflag && params->eflag));
+	return !(params->lflag || params->dflag);
 }
 
 static int zynqimage_check_image_types(uint8_t type)