vac(1), ec(2), usb(3), hjfs(8): fix source reference

sys/man/1/vac

@@ -169,8 +169,6 @@ to standard error.
 If listing files, print metadata in addition to the names.
 .SH SOURCE
 .B /sys/src/cmd/vac
-.br
-.B /sys/src/cmd/unvac
 .SH "SEE ALSO"
 .IR vacfs (4),
 .IR venti (8)

sys/man/2/ec

@@ -108,7 +108,7 @@ in case of error
 failing
 .IR malloc (2)).
 .SH SOURCE
-.B /sys/src/libsec/ec.c
+.B /sys/src/libsec/port/ecc.c
 .SH SEE ALSO
 .I
 Standards for Efficient Cryptography (SEC) 1: Elliptic Curve Cryptography

sys/man/3/usb

@@ -517,9 +517,9 @@ root of the USB interface
 .SH SOURCE
 .B /sys/src/9/port/usb.h
 .br
-.B /sys/src/9/pc/devusb.c
+.B /sys/src/9/port/devusb.c
 .br
-.B /sys/src/9/pc/usb?hci.c
+.B /sys/src/9/*/usb*.c
 .SH "SEE ALSO"
 .IR nusb (2),
 .IR nusb (4),

sys/man/8/hjfs

@@ -196,7 +196,7 @@ Check disk usage (output appears on the system console).
 .SH SEE ALSO
 .IR hjfs (4)
 .SH SOURCE
-.B /sys/src/hjfs
+.B /sys/src/cmd/hjfs
 .SH BUGS
 .B Debug-chdeind
 should perhaps be less crazy and have a portable interface.