tests: portability fixes

* tests/stat.test: dd obs= is not portable, use bs= instead.
* tests/stat32-v.test: Likewise.
* tests/stat64-v.test: Likewise.
* tests/net.test: Use $* instead of $@ in the quoted string.
* tests/net-fd.test: Likewise.
* tests/statfs.test: Quote { and } in regexps.
* tests/caps.awk: Likewise.
* tests/getdents.awk: Likewise.
* tests/net-yy-accept.awk: Likewise.
* tests/net-yy-connect.awk: Likewise.
* tests/sigaction.awk: Likewise.
* tests/unix-yy-accept.awk: Likewise.
* tests/unix-yy-connect.awk: Likewise.
diff --git a/tests/unix-yy-connect.awk b/tests/unix-yy-connect.awk
index 5610192..bbbcff9 100644
--- a/tests/unix-yy-connect.awk
+++ b/tests/unix-yy-connect.awk
@@ -5,7 +5,7 @@
 
   r_i = "[1-9][0-9]*"
   r_close_listen = "^close\\(0<UNIX:[" r_i ",\"" addr "\"]>\\) += 0$"
-  r_connect = "^connect\\(1<UNIX:\\[(" r_i ")\\]>, {sa_family=AF_(LOCAL|UNIX|FILE), sun_path=\"" addr "\"}, " addrlen "\\) += 0$"
+  r_connect = "^connect\\(1<UNIX:\\[(" r_i ")\\]>, \\{sa_family=AF_(LOCAL|UNIX|FILE), sun_path=\"" addr "\"\\}, " addrlen "\\) += 0$"
 }
 
 NR == 1 && /^socket\(PF_(LOCAL|UNIX|FILE), SOCK_STREAM, 0\) += 1$/ {next}