fm10k: fix typos on fall through comments

Newer versions of GCC since version 7 now warn when a case statement may
fall through without an explicit comment. "Fallthough" does not count as
it is misspelled. Fix the typos for these comments to appease the new
warnings.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k_mbx.c

 /* Intel(R) Ethernet Switch Host Interface Driver
- * Copyright(c) 2013 - 2016 Intel Corporation.
+ * Copyright(c) 2013 - 2017 Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -1586,7 +1586,7 @@ s32 fm10k_pfvf_mbx_init(struct fm10k_hw *hw, struct fm10k_mbx_info *mbx,
 			mbx->mbmem_reg = FM10K_MBMEM_VF(id, 0);
 			break;
 		}
-		/* fallthough */
+		/* fall through */
 	default:
 		return FM10K_MBX_ERR_NO_MBX;
 	}

drivers/net/ethernet/intel/fm10k/fm10k_pf.c

 /* Intel(R) Ethernet Switch Host Interface Driver
- * Copyright(c) 2013 - 2016 Intel Corporation.
+ * Copyright(c) 2013 - 2017 Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -1334,19 +1334,19 @@ static u8 fm10k_iov_supported_xcast_mode_pf(struct fm10k_vf_info *vf_info,
 	case FM10K_XCAST_MODE_PROMISC:
 		if (vf_flags & FM10K_VF_FLAG_PROMISC_CAPABLE)
 			return FM10K_XCAST_MODE_PROMISC;
-		/* fallthough */
+		/* fall through */
 	case FM10K_XCAST_MODE_ALLMULTI:
 		if (vf_flags & FM10K_VF_FLAG_ALLMULTI_CAPABLE)
 			return FM10K_XCAST_MODE_ALLMULTI;
-		/* fallthough */
+		/* fall through */
 	case FM10K_XCAST_MODE_MULTI:
 		if (vf_flags & FM10K_VF_FLAG_MULTI_CAPABLE)
 			return FM10K_XCAST_MODE_MULTI;
-		/* fallthough */
+		/* fall through */
 	case FM10K_XCAST_MODE_NONE:
 		if (vf_flags & FM10K_VF_FLAG_NONE_CAPABLE)
 			return FM10K_XCAST_MODE_NONE;
-		/* fallthough */
+		/* fall through */
 	default:
 		break;
 	}