Formatting fixes

man1/df.1

@@ -166,7 +166,7 @@ options.  By default, no filesystem types are omitted.
 .TP
 .B "\-v"
 Ignored; for compatibility with System V versions of
-.B df .
+.BR df .
 .SH "GNU STANDARD OPTIONS"
 .TP
 .B "\-\-help"

man1/time.1

@@ -246,7 +246,7 @@ to
 .I bug\-utils@prep.ai.mit.edu
 .br
 Please include the version of
-.B time ,
+.BR time ,
 which you can get by running
 .br
 .I time \-\-version

man2/cacheflush.2

@@ -43,7 +43,7 @@ Write back to memory and invalidate the affected valid cache lines.
 .TP
 .B BCACHE
 Same as 
-.B (ICACHE|DCACHE) .
+.BR (ICACHE|DCACHE) .
 .PP
 .SH "RETURN VALUE"
 .B cacheflush

man3/errno.3

@@ -36,7 +36,7 @@ errno \- number of last error
 The 
 .I <errno.h>
 header file defines the integer variable
-.B errno ,
+.BR errno ,
 which is set by system calls and some library functions in the event
 of an error to indicate what went wrong.
 Its value is significant only when the call

man3/rpc.3

@@ -1473,7 +1473,7 @@ service transport, to which it returns a pointer.
 The transport is associated with the socket
 .IR sock ,
 which may be
-.B \s-1RPC_ANYSOCK\s0 ,
+.BR \s-1RPC_ANYSOCK\s0 ,
 in which case a new socket is created.
 If the socket is not bound to a local
 .SM UDP