Documentation: i2c: rename variable "register" to "reg"

The example code provided with the i2c device interface documentation
won't compile since it uses the reserved word "register" to name a
variable.

The compiler fails with this error message:

 error: expected identifier or '(' before '=' token
   __u8 register = 0x20; /* Device register to access */
                 ^

Rename the variable "register" to simply "reg" in the example code.

Another couple of typos has been fixed as well.
[Change "! =" to "!=".]
Signed-off-by: NJose Alarcon Roldan <jose.alarcon.roldan@gmail.com>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/i2c/dev-interface

@@ -57,12 +57,12 @@ Well, you are all set up now. You can now use SMBus commands or plain
 I2C to communicate with your device. SMBus commands are preferred if
 the device supports them. Both are illustrated below.
 
-  __u8 register = 0x10; /* Device register to access */
+  __u8 reg = 0x10; /* Device register to access */
   __s32 res;
   char buf[10];
 
   /* Using SMBus commands */
-  res = i2c_smbus_read_word_data(file, register);
+  res = i2c_smbus_read_word_data(file, reg);
   if (res < 0) {
     /* ERROR HANDLING: i2c transaction failed */
   } else {
@@ -70,11 +70,11 @@ the device supports them. Both are illustrated below.
   }
 
   /* Using I2C Write, equivalent of 
-     i2c_smbus_write_word_data(file, register, 0x6543) */
-  buf[0] = register;
+     i2c_smbus_write_word_data(file, reg, 0x6543) */
+  buf[0] = reg;
   buf[1] = 0x43;
   buf[2] = 0x65;
-  if (write(file, buf, 3) ! =3) {
+  if (write(file, buf, 3) != 3) {
     /* ERROR HANDLING: i2c transaction failed */
   }