AP_Baro: Fix BMP581 initialization error #42918

Job	Run time
build (base)	2m 14s
build (clang)	2m 13s
build-gcc-heli	2m 16s
autotest (sitltest-copter-tests1a)	7m 22s
autotest (sitltest-copter-tests1b)	9m 26s
autotest (sitltest-copter-tests1c)	11m 58s
autotest (sitltest-copter-tests1d)	9m 2s
autotest (sitltest-copter-tests1e)	9m 55s
autotest (sitltest-copter-tests2a)	9m 10s
autotest (sitltest-copter-tests2b)	31m 14s
autotest-heli (sitltest-heli)	10m 36s
	1h 45m 26s

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