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: Jose Alarcon Roldan <[e-mail]>
Signed-off-by: Randy Dunlap <[e-mail]>
Acked-by: Wolfram Sang <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/i2c/dev-interface

···
 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 {
···
   }
 
   /* 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 */
   }