docs: ioctl-number: fix a typo in ioctl-number.rst

"userspace" was misspelled as "userpace".

Signed-off-by: Gabriel Whigham <gabewhigham@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260130042131.51975-1-gabewhigham@gmail.com>

Author: MrBrain295

Documentation/userspace-api/ioctl/ioctl-number.rst

@@ -15,7 +15,7 @@ macros defined in <linux/ioctl.h>:
     ====== ===========================
     _IO    none
     _IOW   write (read from userspace)
-    _IOR   read (write to userpace)
+    _IOR   read (write to userspace)
     _IOWR  write and read
     ====== ===========================