Fix a common typo in source code comments

- s/concurently/concurrently/

MFC after:	3 days

sys/dev/acpica/acpi_video.c

@@ -233,7 +233,7 @@ acpi_video_push_evdev_event(struct evdev_dev *evdev, UINT32 notify)
 	int i;
 	uint16_t key;
 
-	/* Do not allow to execute 2 instances this routine concurently */
+	/* Do not allow to execute 2 instances this routine concurrently */
 	ACPI_SERIAL_ASSERT(video_output);
 
 	for (i = 0; i < nitems(acpi_video_evdev_map); i++) {

sys/dev/aic7xxx/aic79xx.h

@@ -288,7 +288,7 @@ typedef enum {
 	 */
 	AHD_NONPACKFIFO_BUG	= 0x4000,
 	/*
-	 * Writing to a DFF SCBPTR register may fail if concurent with
+	 * Writing to a DFF SCBPTR register may fail if concurrent with
 	 * a hardware write to the other DFF SCBPTR register.  This is
 	 * not currently a concern in our sequencer since all chips with
 	 * this bug have the AHD_NONPACKFIFO_BUG and all writes of concern

sys/dev/gpio/gpiopps.c

@@ -130,7 +130,7 @@ gpiopps_ifltr(void *arg)
 	 * written only by the pps_capture() routine and read only by the
 	 * pps_event() routine.  We don't need lock-based management of access
 	 * to the capture area because we have time-based access management:  we
-	 * can't be reading and writing concurently because we can't be running
+	 * can't be reading and writing concurrently because we can't be running
 	 * both the threaded and filter handlers concurrently (because a new
 	 * hardware interrupt can't happen until the threaded handler for the
 	 * current interrupt exits, after which the system does the EOI that