[ostream.seeks] clarify boolean expression

Author: Eisenwave

source/iostreams.tex

@@ -6269,7 +6269,7 @@
 \pnum
 \returns
 If
-\tcode{fail() != false},
+\tcode{fail()} is \keyword{true},
 returns
 \tcode{pos_type(-1)}
 to indicate failure.
@@ -6286,7 +6286,7 @@
 \pnum
 \effects
 If
-\tcode{fail() != true},
+\tcode{fail()} is \keyword{false},
 executes
 \tcode{rdbuf()->pubseekpos(pos, ios_base::out)}.
 In case of failure, the function calls
@@ -6308,7 +6308,7 @@
 \pnum
 \effects
 If
-\tcode{fail() != true},
+\tcode{fail()} is \keyword{false},
 executes
 \tcode{rdbuf()->pubseekoff(off, dir, ios_base::out)}.
 In case of failure, the function calls \tcode{setstate(failbit)}