ioctl.2: Rename 'd' argument to 'fd' in text

In most other manpages file descriptors are called 'fd'.
This patches renames attribute 'd' to 'fd'.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/ioctl.2

@@ -44,7 +44,7 @@ ioctl \- control device
 .SH SYNOPSIS
 .B #include <sys/ioctl.h>
 .sp
-.BI "int ioctl(int " d ", unsigned long " request ", ...);"
+.BI "int ioctl(int " fd ", unsigned long " request ", ...);"
 .\" POSIX says 'request' is int, but glibc has the above
 .\" See https://bugzilla.kernel.org/show_bug.cgi?id=42705
 .SH DESCRIPTION
@@ -56,7 +56,7 @@ In particular, many operating characteristics of character special files
 .BR ioctl ()
 requests.
 The argument
-.I d
+.I fd
 must be an open file descriptor.
 .PP
 The second argument is a device-dependent request code.
@@ -94,7 +94,7 @@ is set appropriately.
 .SH ERRORS
 .TP 0.7i
 .B EBADF
-.I d
+.I fd
 is not a valid descriptor.
 .TP
 .B EFAULT
@@ -108,13 +108,13 @@ or
 is not valid.
 .TP
 .B ENOTTY
-.I d
+.I fd
 is not associated with a character special device.
 .TP
 .B ENOTTY
 The specified request does not apply to the kind of object that the
 descriptor
-.I d
+.I fd
 references.
 .SH CONFORMING TO
 No single standard.