pkg/nydussdk: add more context on returning errors

[eryugey]

So that we know where does that error come from, and make debug easier.

Fixes: #26
Signed-off-by: Eryu Guan [email protected]

[codecov-commenter]

Codecov Report

Merging #27 (bfd35b9) into main (cc06993) will increase coverage by 0.05%.
The diff coverage is 13.33%.

@@            Coverage Diff             @@
##             main      #27      +/-   ##
==========================================
+ Coverage   34.41%   34.46%   +0.05%     
==========================================
  Files          18       18              
  Lines        1293     1294       +1     
==========================================
+ Hits          445      446       +1     
  Misses        777      777              
  Partials       71       71              

Impacted Files	Coverage Δ
pkg/nydussdk/client.go	29.54% <13.33%> (+0.80%)	⬆️

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[imeoer]

LGTM, should also add an error wrap to the waitUntilSocketReady call?

[eryugey]

LGTM, should also add an error wrap to the waitUntilSocketReady call?

Thought about that too, but at last I decide to add context only to public functions, as the errors returned by internal functions like waitUntilSocketReady() will be captured by public functions as well. The only exception is handleMountError(), it's an internal function, but used to handle errors, so I added context to it as well.