random.4: Minor fixes

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

man4/random.4

@@ -37,8 +37,8 @@ The generator also keeps an estimate of the
 number of bits of noise in the entropy pool.
 From this entropy pool random numbers are created.
 .LP
-When read, the \fI/dev/random\fP device will only return random bytes
-within the estimated number of bits of noise in the entropy
+When read, the \fI/dev/random\fP device will return random bytes
+only within the estimated number of bits of noise in the entropy
 pool.
 \fI/dev/random\fP should be suitable for uses that need very
 high quality randomness such as one-time pad or key generation.
@@ -48,13 +48,13 @@ If
 .BR open (2)
 is called for
 .I /dev/random
-with flag
+with the flag
 .BR O_NONBLOCK ,
 a subsequent
 .BR read (2)
 will not block if the requested number of bytes is not available.
 Instead, the available bytes are returned.
-If no byte is available
+If no byte is available,
 .BR read (2)
 will return -1 and
 .I errno
@@ -77,8 +77,8 @@ has no effect when opening
 .IR /dev/urandom .
 When calling
 .BR read (2)
-for device
-.I /dev/urandom
+for the device
+.IR /dev/urandom ,
 signals will not be handled until after the requested random bytes
 have been generated.
 .LP
@@ -127,8 +127,8 @@ The amount of seed material required to generate a cryptographic key
 equals the effective key size of the key.
 For example, a 3072-bit RSA
 or Diffie-Hellman private key has an effective key size of 128 bits
-(it requires about 2^128 operations to break) so a key generator only
-needs 128 bits (16 bytes) of seed material from
+(it requires about 2^128 operations to break) so a key generator
+needs only 128 bits (16 bytes) of seed material from
 .IR /dev/random .
 
 While some safety margin above that minimum is reasonable, as a guard