platform: mellanox: mlx-platform: Initialize shift variable to 0

Initialize shift variable in mlxplat_mlxcpld_verify_bus_topology()
to 0 to avoid the following compile error:

drivers/platform/x86/mlx-platform.c:6013
 mlxplat_mlxcpld_verify_bus_topology() error: uninitialized symbol 'shift'.

Fixes: 50b823fd ("platform: mellanox: mlx-platform: Move bus shift assignment out of the loop")
Cc: Vadim Pasternak <vadimp@nvidia.com>
Cc: Michael Shych <michaelsh@nvidia.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230307105842.286118-1-hdegoede@redhat.com

drivers/platform/x86/mlx-platform.c

@@ -5980,7 +5980,7 @@ MODULE_DEVICE_TABLE(dmi, mlxplat_dmi_table);
 static int mlxplat_mlxcpld_verify_bus_topology(int *nr)
 {
 	struct i2c_adapter *search_adap;
-	int shift, i;
+	int i, shift = 0;
 
 	/* Scan adapters from expected id to verify it is free. */
 	*nr = MLXPLAT_CPLD_PHYS_ADAPTER_DEF_NR;