Airspeed: Use shorter perf names

src/drivers/airspeed/airspeed.cpp

@@ -80,7 +80,7 @@
 Airspeed::Airspeed(int bus, int address, unsigned conversion_interval, const char *path) :
 	I2C("Airspeed", path, bus, address, 100000),
 	_reports(nullptr),
-	_buffer_overflows(perf_alloc(PC_COUNT, "airspeed_buffer_overflows")),
+	_buffer_overflows(perf_alloc(PC_COUNT, "aspd_buf_of")),
 	_max_differential_pressure_pa(0),
 	_sensor_ok(false),
 	_last_published_sensor_ok(true), /* initialize differently to force publication */
@@ -91,8 +91,8 @@ Airspeed::Airspeed(int bus, int address, unsigned conversion_interval, const cha
 	_subsys_pub(nullptr),
 	_class_instance(-1),
 	_conversion_interval(conversion_interval),
-	_sample_perf(perf_alloc(PC_ELAPSED, "airspeed_read")),
-	_comms_errors(perf_alloc(PC_COUNT, "airspeed_comms_errors"))
+	_sample_perf(perf_alloc(PC_ELAPSED, "aspd_read")),
+	_comms_errors(perf_alloc(PC_COUNT, "aspd_com_err"))
 {
 	// enable debug() calls
 	_debug_enabled = false;