cpuload: Fix wrong idle thread load #1351

Job	Run time
variables	1s
fc_matrix (pixhawk) / build	6m 12s
fc_matrix (saluki-pi_custom_keys, Tools/saluki-sec-scripts/custom_keys/saluki-pi/px4_bin_ed25519_... / build	9m 13s
fc_matrix (saluki-pi_amp) / build	9m 12s
fc_matrix (fmu-v6xrt) / build	6m 53s
fc_matrix (saluki-pi_default) / build	9m 0s
fc_matrix (saluki-pi_flat) / build	6m 29s
fc_matrix (saluki-v2_amp) / build	11m 54s
fc_matrix (saluki-v2_custom_keys, Tools/saluki-sec-scripts/custom_keys/saluki-v2/px4_bin_ed25519_... / build	9m 34s
fc_matrix (saluki-v2_default) / build	8m 54s
fc_matrix (saluki-v2_flat) / build	7m 26s
fc_matrix (saluki-v3_amp) / build	9m 13s
fc_matrix (saluki-v3_custom_keys, Tools/saluki-sec-scripts/custom_keys/saluki-v3/px4_bin_ed25519_... / build	9m 1s
fc_matrix (saluki-v3_flat) / build	6m 38s
fc_matrix (saluki-v3_default) / build	8m 49s
build px4fwupdater	2m 3s
upload px4fwupdater to docker registry	1m 20s
upload builds to UAE artifactory	2m 49s
upload px4fwupdater to UAE docker registry	0s
	2h 4m 41s

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