client: add missing error checks

[Danielius1922]

No description provided.

[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

61.3% Coverage
0.0% Duplication

[codecov-commenter]

Codecov Report

Merging #248 (952d61b) into main (6a5a663) will increase coverage by 0.10%.
The diff coverage is 55.26%.

@@            Coverage Diff             @@
##             main     #248      +/-   ##
==========================================
+ Coverage   60.59%   60.69%   +0.10%     
==========================================
  Files          63       63              
  Lines        3987     3987              
==========================================
+ Hits         2416     2420       +4     
+ Misses       1239     1232       -7     
- Partials      332      335       +3     

Impacted Files	Coverage Δ
client/getDevices.go	65.60% <ø> (+2.02%)	⬆️
client/core/observeResource.go	53.92% <25.00%> (ø)
client/observeResource.go	65.57% <61.53%> (-1.29%)	⬇️
client/observeDeviceResources.go	65.04% <62.50%> (ø)
client/observeDevices.go	68.05% <62.50%> (ø)
client/refDevice.go	91.48% <100.00%> (ø)
client/core/disownDevice.go	75.75% <0.00%> (+3.03%)	⬆️
client/core/maintenance.go	70.37% <0.00%> (+7.40%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6a5a663...952d61b. Read the comment docs.