Fix errcheck issues in server/channels/utils/fileutils/fileutils_test…

….go (mattermost#28919)

server/.golangci.yml

@@ -252,7 +252,6 @@ issues:
         channels/store/storetest/thread_store.go|\
         channels/store/storetest/user_store.go|\
         channels/testlib/helper.go|\
-        channels/utils/fileutils/fileutils_test.go|\
         channels/utils/license_test.go|\
         channels/web/oauth.go|\
         channels/web/oauth_test.go|\

server/channels/utils/fileutils/fileutils_test.go

@@ -27,7 +27,10 @@ func TestFindFile(t *testing.T) {
 		//         tmpDir5/
 		tmpDir1, err := os.MkdirTemp("", "")
 		require.NoError(t, err)
-		defer os.RemoveAll(tmpDir1)
+		defer func() {
+			err = os.RemoveAll(tmpDir1)
+			require.NoError(t, err)
+		}()
 
 		tmpDir2, err := os.MkdirTemp(tmpDir1, "")
 		require.NoError(t, err)
@@ -52,10 +55,10 @@ func TestFindFile(t *testing.T) {
 		}
 
 		testCases := []testCase{}
-
 		for _, fileName := range []string{"file1.json", "file2.xml", "other.txt"} {
 			filePath := filepath.Join(tmpDir1, fileName)
-			require.NoError(t, os.WriteFile(filePath, []byte("{}"), 0600))
+			err = os.WriteFile(filePath, []byte("{}"), 0600)
+			require.NoError(t, err)
 
 			// Relative paths end up getting symlinks fully resolved, so use this below as necessary.
 			filePathResolved, err := filepath.EvalSymlinks(filePath)
@@ -112,10 +115,15 @@ func TestFindFile(t *testing.T) {
 				if testCase.Cwd != nil {
 					prevDir, err := os.Getwd()
 					require.NoError(t, err)
-					defer os.Chdir(prevDir)
-					os.Chdir(*testCase.Cwd)
-				}
 
+					err = os.Chdir(*testCase.Cwd)
+					require.NoError(t, err)
+
+					defer func() {
+						err = os.Chdir(prevDir)
+						require.NoError(t, err)
+					}()
+				}
 				assert.Equal(t, testCase.Expected, FindFile(testCase.FileName))
 			})
 		}