s/nonnegative/non-negative/

man2/intro.2

@@ -137,7 +137,7 @@ codes.
 You need to read the source to be sure how it will return errors.
 Usually, it is the negative of a standard error code, e.g., \-\fBEPERM\fP.
 The _syscall() macros will return the result \fIr\fP of the system call
-when \fIr\fP is nonnegative, but will return \-1 and set the variable
+when \fIr\fP is non-negative, but will return \-1 and set the variable
 .I errno
 to \-\fIr\fP when \fIr\fP is negative.
 For the error codes, see

man2/ioctl.2

@@ -83,7 +83,7 @@ Usually, on success zero is returned.
 A few
 .BR ioctl ()
 requests use the return value as an output parameter
-and return a nonnegative value on success.
+and return a non-negative value on success.
 On error, \-1 is returned, and
 .I errno
 is set appropriately.

man2/msgget.2

@@ -138,7 +138,7 @@ verified, and a check is made to see if it is marked for
 destruction.
 .SH "RETURN VALUE"
 If successful, the return value will be the message queue identifier (a
-nonnegative integer), otherwise \-1
+non-negative integer), otherwise \-1
 with
 .I errno
 indicating the error.

man2/semctl.2

@@ -341,7 +341,7 @@ with
 .I errno
 indicating the error.
 
-Otherwise the system call returns a nonnegative value depending on
+Otherwise the system call returns a non-negative value depending on
 .I cmd
 as follows:
 .TP 11

man2/semget.2

@@ -157,7 +157,7 @@ verified.
 .\" and a check is made to see if it is marked for destruction.
 .SH "RETURN VALUE"
 If successful, the return value will be the semaphore set identifier
-(a nonnegative integer), otherwise \-1
+(a non-negative integer), otherwise \-1
 is returned, with
 .I errno
 indicating the error.