Fix the usage of posix_fallocate() so that it correctly responds to

EINVAL returns.

FossilOrigin-Name: ce2c3e7a875ede4366c48660ae8239d2b74e5f690ad5059844a45f1164f41e61

diff --cc manifest
index ac797e0d29a2adbcb783c10633df0a4c7abf22eb,5dcbfbfcfa1adbe8d7ae5141da48fe28f0130370..0a38981e1096d3cb425ea4d859d473a8f82ff9b6
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Update\sa\stest\scase\sin\smalloc5.test\sto\stake\sinto\saccount\sthat\smalloc()\nsometimes\sreturns\sslightly\smore\sspace\sthan\srequested.
- D 2018-06-02T17:00:57.712
 -C Proposed\sfix\sfor\sthe\suse\sof\sposix_fallocate()\sso\sthat\sit\shandles\sEINVAL\nreturns\scorrectly.
 -D 2018-06-02T14:37:39.510
++C Fix\sthe\susage\sof\sposix_fallocate()\sso\sthat\sit\scorrectly\sresponds\sto\nEINVAL\sreturns.
++D 2018-06-02T19:01:54.408
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F Makefile.in bfc40f350586923e0419d2ea4b559c37ec10ee4b6e210e08c14401f8e340f0da
@@@ -1730,7 -1730,10 +1730,8 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
--P e336cf00486bdc0ec04ecded2b7c874d73a87e6aba3544e3678bedfb9a4af3b6
- R 6e46205cb0ef6ad7de1d5ad2d4fadd35
- U dan
- Z ef3783ba7b32ff9195245e676b3fce8c
 -R da9d2a3150755067fb60b396ecd1f393
 -T *branch * einval-from-fallocate
 -T *sym-einval-from-fallocate *
 -T -sym-trunk *
++P 3d5eae1c26353cdee89f31f1293b05c0edb494c775ba0912d9b4fda9ab0ef304 ab3a5539db82814cafb832cdaebd1e14566139306453ef9cdba6b244a994fe0b
++R 64e7a20d51f9d1438ac9592daa9dd6bf
++T +closed ab3a5539db82814cafb832cdaebd1e14566139306453ef9cdba6b244a994fe0b
+ U drh
 -Z 0912fba33d0304ba068cf7360fbe56ad
++Z 8bf90c20199723dfc867a912d22476ec

diff --cc manifest.uuid
index a653482299c4c0ac34dd825d20ad84ee5af17987,1be70675a36f55a8224ec2bf36a6985e1fa90a91..cb15120d4f3bbc229cd820d5d6d29850bbf328b1
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 3d5eae1c26353cdee89f31f1293b05c0edb494c775ba0912d9b4fda9ab0ef304
 -ab3a5539db82814cafb832cdaebd1e14566139306453ef9cdba6b244a994fe0b
++ce2c3e7a875ede4366c48660ae8239d2b74e5f690ad5059844a45f1164f41e61