Remove statement is unreachable warning in MbedCRC.h

The code removed appears unnecessary given that the switch case below
also handles the case where the polynomial is `POLY_32BIT_REV_ANSI`

Author: hugueskamba

drivers/MbedCRC.h

@@ -514,22 +514,19 @@ class MbedCRC {
         MBED_STATIC_ASSERT(width <= 32, "Max 32-bit CRC supported");
 
 #if DEVICE_CRC
-        if (POLY_32BIT_REV_ANSI == polynomial) {
-            _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI;
-            _mode = TABLE;
-            return;
-        }
-        crc_mbed_config_t config;
-        config.polynomial  = polynomial;
-        config.width       = width;
-        config.initial_xor = _initial_value;
-        config.final_xor   = _final_xor;
-        config.reflect_in  = _reflect_data;
-        config.reflect_out = _reflect_remainder;
-
-        if (hal_crc_is_supported(&config)) {
-            _mode = HARDWARE;
-            return;
+        if (POLY_32BIT_REV_ANSI != polynomial) {
+            crc_mbed_config_t config;
+            config.polynomial  = polynomial;
+            config.width       = width;
+            config.initial_xor = _initial_value;
+            config.final_xor   = _final_xor;
+            config.reflect_in  = _reflect_data;
+            config.reflect_out = _reflect_remainder;
+
+            if (hal_crc_is_supported(&config)) {
+                _mode = HARDWARE;
+                return;
+            }
         }
 #endif