statx.2: Give final argument of call a more meaningful name ('statxbuf')

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/statx.2

@@ -39,7 +39,7 @@ statx \- get file status (extended)
 .BR "#include <fcntl.h>           " "/* Definition of AT_* constants */"
 
 .BI "int statx(int " dirfd ", const char *" pathname ", int " flags ","
-.BI "          unsigned int " mask ", struct statx *" buf );
+.BI "          unsigned int " mask ", struct statx *" statxbuf );
 .fi
 
 .IR Note :
@@ -50,7 +50,7 @@ see NOTES.
 .PP
 This function returns information about a file, storing it in the buffer
 pointed to by
-.IR buf .
+.IR statxbuf .
 The returned buffer is a structure of the following type:
 .PP
 .in +4n
@@ -293,7 +293,7 @@ The returned information
 The status information for the target file is returned in the
 .I statx
 structure pointed to by
-.IR buf .
+.IR statxbuf .
 Included in this is
 .I stx_mask
 which indicates what other information has been returned.
@@ -483,7 +483,7 @@ is not a valid open file descriptor.
 .B EFAULT
 .I pathname
 or
-.I buf
+.I statxbuf
 is NULL or points to a location outside the process's
 accessible address space.
 .TP