do not use `a' quoting style in comments

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

miscutils/adjtimex.c

@@ -1,6 +1,6 @@
 /* vi: set sw=4 ts=4: */
 /*
- * adjtimex.c - read, and possibly modify, the Linux kernel `timex' variables.
+ * adjtimex.c - read, and possibly modify, the Linux kernel 'timex' variables.
  *
  * Originally written: October 1997
  * Last hack: March 2001

miscutils/time.c

@@ -127,13 +127,13 @@ static unsigned long ptok(const unsigned pagesize, const unsigned long pages)
 
 /* summarize: Report on the system use of a command.
 
-   Print the FMT argument except that `%' sequences
-   have special meaning, and `\n' and `\t' are translated into
-   newline and tab, respectively, and `\\' is translated into `\'.
+   Print the FMT argument except that '%' sequences
+   have special meaning, and '\n' and '\t' are translated into
+   newline and tab, respectively, and '\\' is translated into '\'.
 
-   The character following a `%' can be:
+   The character following a '%' can be:
    (* means the tcsh time builtin also recognizes it)
-   % == a literal `%'
+   % == a literal '%'
    C == command name and arguments
 *  D == average unshared data size in K (ru_idrss+ru_isrss)
 *  E == elapsed real (wall clock) time in [hour:]min:sec