Consistently use 'op' in argument names.

This matches changes being made to regularize the man page terminology.

Change-Id: If949cf81a0a0a06f24a4a742e8bf45c53dbd0da1
diff --git a/libc/include/bits/fcntl.h b/libc/include/bits/fcntl.h
index 597aa6e..ee5a6e1 100644
--- a/libc/include/bits/fcntl.h
+++ b/libc/include/bits/fcntl.h
@@ -43,6 +43,6 @@
  *
  * The return value depends on the operation.
  */
-int fcntl(int __fd, int __cmd, ...);
+int fcntl(int __fd, int __op, ...);
 
 __END_DECLS
diff --git a/libc/include/bits/ioctl.h b/libc/include/bits/ioctl.h
index fd31a58..260eb7d 100644
--- a/libc/include/bits/ioctl.h
+++ b/libc/include/bits/ioctl.h
@@ -40,7 +40,7 @@
 /**
  * [ioctl(2)](http://man7.org/linux/man-pages/man2/ioctl.2.html) operates on device files.
  */
-int ioctl(int __fd, int __request, ...);
+int ioctl(int __fd, int __op, ...);
 
 /*
  * Work around unsigned -> signed conversion warnings: many common ioctl
@@ -57,7 +57,7 @@
  */
 #if !defined(BIONIC_IOCTL_NO_SIGNEDNESS_OVERLOAD)
 /* enable_if(1) just exists to break overloading ties. */
-int ioctl(int __fd, unsigned __request, ...) __overloadable __enable_if(1, "") __RENAME(ioctl);
+int ioctl(int __fd, unsigned __op, ...) __overloadable __enable_if(1, "") __RENAME(ioctl);
 #endif
 
 __END_DECLS
diff --git a/libc/include/bits/lockf.h b/libc/include/bits/lockf.h
index ec6e53c..d9f5987 100644
--- a/libc/include/bits/lockf.h
+++ b/libc/include/bits/lockf.h
@@ -56,12 +56,12 @@
  *
  * See also flock().
  */
-int lockf(int __fd, int __cmd, off_t __length) __RENAME_IF_FILE_OFFSET64(lockf64) __INTRODUCED_IN(24);
+int lockf(int __fd, int __op, off_t __length) __RENAME_IF_FILE_OFFSET64(lockf64) __INTRODUCED_IN(24);
 
 /**
  * Like lockf() but allows using a 64-bit length
  * even from a 32-bit process without `_FILE_OFFSET_BITS=64`.
  */
-int lockf64(int __fd, int __cmd, off64_t __length) __INTRODUCED_IN(24);
+int lockf64(int __fd, int __op, off64_t __length) __INTRODUCED_IN(24);
 
 __END_DECLS