[storage] Rename NVMf -> Nvme

[glimchb]

Naming NVMf caused proto to force "nv_mf" syntax which is weird.
Unify the naming to Nvme format utilized throughout all API components.

Signed-off-by: Boris Glimcher [email protected]

[codecov]

Codecov Report

Merging #519 (5157df8) into main (1c9d83b) will not change coverage.
The diff coverage is 81.70%.

@@           Coverage Diff           @@
##             main     #519   +/-   ##
=======================================
  Coverage   70.75%   70.75%           
=======================================
  Files          21       21           
  Lines        3406     3406           
=======================================
  Hits         2410     2410           
  Misses        891      891           
  Partials      105      105           

Impacted Files	Coverage Δ
pkg/backend/nvme_path.go	58.46% <75.47%> (ø)
pkg/backend/nvme_controller.go	73.72% <92.59%> (ø)
pkg/backend/backend.go	100.00% <100.00%> (ø)