Fix missing field initializer in cachelib/navy/common/FdpNvme.cpp +1

Summary:
The LLVM warning `-Wmissing-field-initializers` has found one or more structs in this diff's files which were missing field initializers.

This can be unintended such as:
```
my_struct s1 = {0}; // Initializes *only* the first field to zero; others to default values
my_struct s2 = {}; // Initializes *all* fields to default values (often zero)
```
or it may be because only some of the members of a struct are initialized, perhaps because the items were added to the struct but not every instance of it was updated.

To fix the problem, I've either used `{}` to initialize all fields to default or added appropriate default initializations to the missing fields.

 - If you approve of this diff, please use the "Accept & Ship" button :-)

Reviewed By: yfeldblum

Differential Revision: D69753297

fbshipit-source-id: 98e0335038bd0125af4f03a43e67960c41ef3d8b

Author: r-barnes

cachelib/navy/common/FdpNvme.cpp

@@ -88,15 +88,14 @@ int FdpNvme::nvmeIOMgmtRecv(uint32_t nsid,
   uint32_t cdw10 = (op & 0xf) | (op_specific & 0xff << 16);
   uint32_t cdw11 = (data_len >> 2) - 1; // cdw11 is 0 based
 
-  struct nvme_passthru_cmd cmd = {
-      .opcode = nvme_cmd_io_mgmt_recv,
-      .nsid = nsid,
-      .addr = (uint64_t)(uintptr_t)data,
-      .data_len = data_len,
-      .cdw10 = cdw10,
-      .cdw11 = cdw11,
-      .timeout_ms = NVME_DEFAULT_IOCTL_TIMEOUT,
-  };
+  struct nvme_passthru_cmd cmd = {};
+  cmd.opcode = nvme_cmd_io_mgmt_recv;
+  cmd.nsid = nsid;
+  cmd.addr = (uint64_t)(uintptr_t)data;
+  cmd.data_len = data_len;
+  cmd.cdw10 = cdw10;
+  cmd.cdw11 = cdw11;
+  cmd.timeout_ms = NVME_DEFAULT_IOCTL_TIMEOUT;
 
   return ioctl(file_.fd(), NVME_IOCTL_IO_CMD, &cmd);
 }