correct gpio.txt typos

Corrected sysfs gpio chip node name and fixed punctuation.
Signed-off-by: Dominik D. Geyer <dominik.geyer@gmx.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/gpio.txt

@@ -380,7 +380,7 @@ rare; use gpiochip_remove() when it is unavoidable.
 
 Most often a gpio_chip is part of an instance-specific structure with state
 not exposed by the GPIO interfaces, such as addressing, power management,
-and more.  Chips such as codecs will have complex non-GPIO state,
+and more.  Chips such as codecs will have complex non-GPIO state.
 
 Any debugfs dump method should normally ignore signals which haven't been
 requested as GPIOs.  They can use gpiochip_is_requested(), which returns
@@ -531,7 +531,7 @@ and have the following read/write attributes:
 		This file exists only if the pin can be configured as an
 		interrupt generating input pin.
 
-GPIO controllers have paths like /sys/class/gpio/chipchip42/ (for the
+GPIO controllers have paths like /sys/class/gpio/gpiochip42/ (for the
 controller implementing GPIOs starting at #42) and have the following
 read-only attributes: